The news is a major breakthrough in the unprecedented two-week struggle to find out what happened to Flight 370, which disappeared shortly after takeoff from Kuala Lumpur to Beijing with 239 passengers and crew aboard on March 8.

Dressed in a black suit, Najib announced the news “with deep sadness and regret” in a brief news conference late Monday night.

He said Malaysia Airlines has informed the families of passengers of the plane’s fate.

Najib said the information was based on an unprecedented analysis of satellite data from Inmarsat.

Earlier in the day, Chinese and Australian planes spotted several objects in an area of the southern Indian Ocean identified by multiple satellite images as containing possible debris from Malaysia Airlines Flight 370.

Australian Prime Minister Tony Abbott says the crew on board an Australian P3 Orion located two objects – the first grey or green and circular, the second orange and rectangular.

Malaysians Airlines sent a text message to the victims of the families saying, “Malaysia Airlines deeply regrets that we have to assume beyond any reasonable doubt that MH370 has been lost and that none of those on board survived. As you will hear in the next hour from Malaysia’s Prime Minister, we must now accept all evidence suggests the plane went down in the Southern Indian Ocean.”

An Australian P3 Orion aircraft has located two objects in the search zone some 2,500 kilometers (1,550 miles) southwest of Australia – the first grey or green and circular, the second orange and rectangular. An Australian navy supply ship, the HMAS Success, could reach the objects within several hours or by Tuesday morning, Malaysia’s Defense Minister Hishammuddin Hussein said.

A Chinese plane crew, meanwhile, spotted two large objects and several smaller ones spread across several square kilometers (miles), Xinhua News Agency reported. At least one of the items – a white, square-shaped object – was captured on a camera aboard the plane. A Chinese icebreaker, the Snow Dragon, was headed toward the area and would arrive Tuesday morning.

Malaysia Airlines Flight 370 went missing over the Gulf of Thailand on March 8.

One of the passengers aboard the Malaysia Airlines flight is a Pittsburgh resident.

Mei Ling Chng, of South Park, was one of the 239 people on the plane.

Ling is a process engineer at the Monongahela location of Flexsys America LP.

The U.S. Pacific command said it was sending a Towed Pinger Locator to the region in case a debris field is found. The equipment, which is pulled behind a vessel at slow speeds, has highly sensitive listening capability that can detect “pings” from a plane’s so-called black box down to a depth of 20,000 feet (6,100 meters).

An Australian navy support vessel, the Ocean Shield, equipped with acoustic detection equipment, was also moving into the search zone and would arrive in three or four days.

Australia, China, the U.S., Japan and New Zealand have all contributed planes or ships to the search effort in the southern Indian Ocean. At least 14 planes and nine ships are involved or headed toward the search zone.